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Hassanpour MS, Merlin S, Federer F, Zaidi Q, Angelucci A. Primate V2 Receptive Fields Derived from Anatomically Identified Large-Scale V1 Inputs. bioRxiv 2024:2024.03.22.586002. [PMID: 38585792 PMCID: PMC10996519 DOI: 10.1101/2024.03.22.586002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
In the primate visual system, visual object recognition involves a series of cortical areas arranged hierarchically along the ventral visual pathway. As information flows through this hierarchy, neurons become progressively tuned to more complex image features. The circuit mechanisms and computations underlying the increasing complexity of these receptive fields (RFs) remain unidentified. To understand how this complexity emerges in the secondary visual area (V2), we investigated the functional organization of inputs from the primary visual cortex (V1) to V2 by combining retrograde anatomical tracing of these inputs with functional imaging of feature maps in macaque monkey V1 and V2. We found that V1 neurons sending inputs to single V2 orientation columns have a broad range of preferred orientations, but are strongly biased towards the orientation represented at the injected V2 site. For each V2 site, we then constructed a feedforward model based on the linear combination of its anatomically-identified large-scale V1 inputs, and studied the response proprieties of the generated V2 RFs. We found that V2 RFs derived from the linear feedforward model were either elongated versions of V1 filters or had spatially complex structures. These modeled RFs predicted V2 neuron responses to oriented grating stimuli with high accuracy. Remarkably, this simple model also explained the greater selectivity to naturalistic textures of V2 cells compared to their V1 input cells. Our results demonstrate that simple linear combinations of feedforward inputs can account for the orientation selectivity and texture sensitivity of V2 RFs.
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Lawther AJ, Zieba J, Fang Z, Furlong TM, Conn I, Govindaraju H, Choong LLY, Turner N, Siddiqui KS, Bridge W, Merlin S, Hyams TC, Killingsworth M, Eapen V, Clarke RA, Walker AK. Antioxidant Behavioural Phenotype in the Immp2l Gene Knock-Out Mouse. Genes (Basel) 2023; 14:1717. [PMID: 37761857 PMCID: PMC10531238 DOI: 10.3390/genes14091717] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/16/2023] [Accepted: 08/21/2023] [Indexed: 09/29/2023] Open
Abstract
Mitochondrial dysfunction is strongly associated with autism spectrum disorder (ASD) and the Inner mitochondrial membrane protein 2-like (IMMP2L) gene is linked to autism inheritance. However, the biological basis of this linkage is unknown notwithstanding independent reports of oxidative stress in association with both IMMP2L and ASD. To better understand IMMP2L's association with behaviour, we developed the Immp2lKD knockout (KO) mouse model which is devoid of Immp2l peptidase activity. Immp2lKD -/- KO mice do not display any of the core behavioural symptoms of ASD, albeit homozygous Immp2lKD -/- KO mice do display increased auditory stimulus-driven instrumental behaviour and increased amphetamine-induced locomotion. Due to reports of increased ROS and oxidative stress phenotypes in an earlier truncated Immp2l mouse model resulting from an intragenic deletion within Immp2l, we tested whether high doses of the synthetic mitochondrial targeted antioxidant (MitoQ) could reverse or moderate the behavioural changes in Immp2lKD -/- KO mice. To our surprise, we observed that ROS levels were not increased but significantly lowered in our new Immp2lKD -/- KO mice and that these mice had no oxidative stress-associated phenotypes and were fully fertile with no age-related ataxia or neurodegeneration as ascertained using electron microscopy. Furthermore, the antioxidant MitoQ had no effect on the increased amphetamine-induced locomotion of these mice. Together, these findings indicate that the behavioural changes in Immp2lKD -/- KO mice are associated with an antioxidant-like phenotype with lowered and not increased levels of ROS and no oxidative stress-related phenotypes. This suggested that treatments with antioxidants are unlikely to be effective in treating behaviours directly resulting from the loss of Immp2l/IMMP2L activity, while any behavioural deficits that maybe associated with IMMP2L intragenic deletion-associated truncations have yet to be determined.
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Affiliation(s)
- Adam J. Lawther
- Laboratory of ImmunoPsychiatry, Neuroscience Research Australia, Randwick, NSW 2031, Australia
| | - Jerzy Zieba
- Laboratory of ImmunoPsychiatry, Neuroscience Research Australia, Randwick, NSW 2031, Australia
- Department of Psychology, University of Rzeszow, 35-310 Rzeszow, Poland
| | - Zhiming Fang
- Discipline of Psychiatry and Mental Health, University of New South Wales, Sydney, NSW 2052, Australia
- Ingham Institute for Applied Medical Research, Sydney, NSW 2170, Australia; (T.C.H.)
| | - Teri M. Furlong
- School of Biomedical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Illya Conn
- Laboratory of ImmunoPsychiatry, Neuroscience Research Australia, Randwick, NSW 2031, Australia
- Schizophrenia Research Laboratory, Neuroscience Research Australia, Randwick, NSW 2031, Australia
| | - Hemna Govindaraju
- Department of Pharmacology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Laura L. Y. Choong
- Department of Pharmacology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Nigel Turner
- Department of Pharmacology, School of Biomedical Sciences, University of New South Wales, Sydney, NSW 2052, Australia
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Khawar Sohail Siddiqui
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Wallace Bridge
- School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney, NSW 2052, Australia
| | - Sam Merlin
- Medical Science, School of Science, Western Sydney University, Campbelltown, Sydney, NSW 2751, Australia
| | - Tzipi Cohen Hyams
- Ingham Institute for Applied Medical Research, Sydney, NSW 2170, Australia; (T.C.H.)
| | - Murray Killingsworth
- Ingham Institute for Applied Medical Research, Sydney, NSW 2170, Australia; (T.C.H.)
- NSW Health Pathology, Liverpool Hospital Campus, 1 Campbell Street, Liverpool, NSW 2107, Australia
| | - Valsamma Eapen
- Discipline of Psychiatry and Mental Health, University of New South Wales, Sydney, NSW 2052, Australia
- Ingham Institute for Applied Medical Research, Sydney, NSW 2170, Australia; (T.C.H.)
- Academic Unit of Infant Child and Adolescent Services (AUCS), South Western Sydney Local Health District, Liverpool, NSW 2170, Australia
| | - Raymond A. Clarke
- Discipline of Psychiatry and Mental Health, University of New South Wales, Sydney, NSW 2052, Australia
- Ingham Institute for Applied Medical Research, Sydney, NSW 2170, Australia; (T.C.H.)
- Academic Unit of Infant Child and Adolescent Services (AUCS), South Western Sydney Local Health District, Liverpool, NSW 2170, Australia
| | - Adam K. Walker
- Laboratory of ImmunoPsychiatry, Neuroscience Research Australia, Randwick, NSW 2031, Australia
- Discipline of Psychiatry and Mental Health, University of New South Wales, Sydney, NSW 2052, Australia
- Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC 3052, Australia
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Leung BK, Merlin S, Walker AK, Lawther AJ, Paxinos G, Eapen V, Clarke R, Balleine BW, Furlong TM. Immp2l knockdown in male mice increases stimulus-driven instrumental behaviour but does not alter goal-directed learning or neuron density in cortico-striatal circuits in a model of Tourette syndrome and autism spectrum disorder. Behav Brain Res 2023; 452:114610. [PMID: 37541448 DOI: 10.1016/j.bbr.2023.114610] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2023] [Revised: 07/22/2023] [Accepted: 08/01/2023] [Indexed: 08/06/2023]
Abstract
Cortico-striatal neurocircuits mediate goal-directed and habitual actions which are necessary for adaptive behaviour. It has recently been proposed that some of the core symptoms of autism spectrum disorder (ASD) and Gilles de la Tourette syndrome (GTS), such as tics and other repetitive behaviours, may emerge because of imbalances in these neurocircuits. We have recently developed a model of ASD and GTS by knocking down Immp2l, a mitochondrial gene frequently associated with these disorders. The current study sought to determine whether Immp2l knockdown (KD) in male mice alters flexible, goal- or cue- driven behaviour using procedures specifically designed to examine response-outcome and stimulus-response associations, which underlie goal-directed and habitual behaviour, respectively. Whether Immp2l KD alters neuron density in cortico-striatal neurocircuits known to regulate these behaviours was also examined. Immp2l KD mice and wild type-like mice (WT) were trained on Pavlovian and instrumental learning procedures where auditory cues predicted food delivery and lever-press responses earned a food outcome. It was demonstrated that goal-directed learning was not changed for Immp2l KD mice compared to WT mice, as lever-press responses were sensitive to changes in the value of the food outcome, and to contingency reversal and degradation. There was also no difference in the capacity of KD mice to form habitual behaviours compared to WT mice following extending training of the instrumental action. However, Immp2l KD mice were more responsive to auditory stimuli paired with food as indicated by a non-specific increase in lever response rates during Pavlovian-to-instrumental transfer. Finally, there were no alterations to neuron density in striatum or any prefrontal cortex or limbic brain structures examined. Thus, the current study suggests that Immp2l is not necessary for learned maladaptive goal or stimulus driven behaviours in ASD or GTS, but that it may contribute to increased capacity for external stimuli to drive behaviour. Alterations to stimulus-driven behaviour could potentially influence the expression of tics and repetitive behaviours, suggesting that genetic alterations to Immp2l may contribute to these core symptoms in ASD and GTS. Given that this is the first application of this battery of instrumental learning procedures to a mouse model of ASD or GTS, it is an important initial step in determining the contribution of known risk-genes to goal-directed versus habitual behaviours, which should be more broadly applied to other rodent models of ASD and GTS in the future.
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Affiliation(s)
- Beatrice K Leung
- Decision Neuroscience Laboratory, School of Psychology, University of New South Wales, Sydney, NSW, Australia
| | - Sam Merlin
- School of Science, Western Sydney University, Campbelltown, Sydney, NSW, Australia
| | - Adam K Walker
- Laboratory of ImmunoPsychiatry, Neuroscience Research Australia, Randwick, NSW, Australia; Discipline of Psychiatry and Mental Health, University of New South Wales, NSW, Australia
| | - Adam J Lawther
- Laboratory of ImmunoPsychiatry, Neuroscience Research Australia, Randwick, NSW, Australia
| | - George Paxinos
- Neuroscience Research Australia, Randwick, NSW, Australia; School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia
| | - Valsamma Eapen
- Discipline of Psychiatry and Mental Health, University of New South Wales, NSW, Australia; Mental Health Research Unit, South Western Sydney Local Health District, Liverpool, Australia
| | - Raymond Clarke
- Ingham Institute, Discipline of Psychiatry, University of New South Wales, Sydney, NSW, Australia
| | - Bernard W Balleine
- Decision Neuroscience Laboratory, School of Psychology, University of New South Wales, Sydney, NSW, Australia
| | - Teri M Furlong
- Neuroscience Research Australia, Randwick, NSW, Australia; School of Biomedical Sciences, University of New South Wales, Sydney, NSW, Australia.
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Merlin S, Vidyasagar T. Optogenetics in primate cortical networks. Front Neuroanat 2023; 17:1193949. [PMID: 37284061 PMCID: PMC10239886 DOI: 10.3389/fnana.2023.1193949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Accepted: 05/08/2023] [Indexed: 06/08/2023] Open
Abstract
The implementation of optogenetics in studies on non-human primates has generally proven quite difficult, but recent successes have paved the way for its rapid increase. Limitations in the genetic tractability in primates, have been somewhat overcome by implementing tailored vectors and promoters to maximize expression and specificity in primates. More recently, implantable devices, including microLED arrays, have made it possible to deliver light deeper into brain tissue, allowing targeting of deeper structures. However, the greatest limitation in applying optogenetics to the primate brain is the complex connections that exist within many neural circuits. In the past, relatively cruder methods such as cooling or pharmacological blockade have been used to examine neural circuit functions, though their limitations were well recognized. In some ways, similar shortcomings remain for optogenetics, with the ability to target a single component of complex neural circuits being the greatest challenge in applying optogenetics to systems neuroscience in primate brains. Despite this, some recent approaches combining Cre-expressing and Cre-dependent vectors have overcome some of these limitations. Here we suggest that optogenetics provides its greatest advantage to systems neuroscientists when applied as a specific tool to complement the techniques of the past, rather than necessarily replacing them.
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Affiliation(s)
- Sam Merlin
- Medical Science, School of Science, Western Sydney University, Campbelltown, NSW, Australia
| | - Trichur Vidyasagar
- Department of Optometry and Vision Sciences, School of Health Science, The University of Melbourne, Parkville, VIC, Australia
- Florey Department of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
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Merlin S, Furlong TM. Habitual behaviour associated with exposure to high-calorie diet is prevented by an orexin-receptor-1 antagonist. Addict Neurosci 2022; 4:100036. [PMID: 37476304 PMCID: PMC10357952 DOI: 10.1016/j.addicn.2022.100036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 07/22/2023]
Abstract
Habitual actions, which are associated with addictive behaviours, contribute to the loss of control of food seeking seen following exposure to calorie-dense foods in rats. Antagonism of orexin-receptor-1 (ORX-R1) has been shown to reduce a range of stimulus-driven feeding behaviours, but have yet to be implicated in the regulation of habitual actions. In the current study, male Long-Evans rats were given 'binge-like' access to high-calorie diet (HCD) or standard chow diet, and were subsequently trained to press a lever for food outcome. When lever responses were tested following outcome devaluation, chow-fed rats displayed goal-directed actions, whereas HCD-exposed rats displayed habitual actions. In study 1, it was shown that systemic administration of the ORX-R1 antagonist, SB-334867, prior to test restored goal-directed behaviour in HCD-exposed rats. In study 2, intra-nigral administration of SB-334867 similarly restored goal-directed behaviour, thereby implicating the substantia nigra as an important site for this effect. This study demonstrates that targeting ORX-R1 reduces habitual food seeking in male rats which may be important for understanding and treating compulsive feeding, obesity and binge eating disorder. This study also implicates the lateral hypothalamus, where ORX is produced, in mediating the expression of habits for the first time, and thus extends on the neurocircuits known to regulate habitual actions. Further investigation is required to determine whether the same effects are also seen in female rats, given that there are recognised sexual dimorphisms in feeding behaviour and a higher incidence of disordered eating in female than male populations.
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Affiliation(s)
- Sam Merlin
- School of Science, Western Sydney University, Campbelltown, NSW 2560, Australia
| | - Teri M. Furlong
- School of Biomedical Sciences, The University of New South Wales, Sydney, NSW 2052, Australia
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
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Bingul A, Merlin S, Carrive P, Killcross S, Furlong TM. Targeting the lateral hypothalamus with short hairpin RNAs reduces habitual behaviour following extended instrumental training in rats. Neurobiol Learn Mem 2022; 193:107657. [DOI: 10.1016/j.nlm.2022.107657] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 06/23/2022] [Accepted: 06/28/2022] [Indexed: 10/17/2022]
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Siu C, Balsor J, Merlin S, Federer F, Angelucci A. A direct interareal feedback-to-feedforward circuit in primate visual cortex. Nat Commun 2021; 12:4911. [PMID: 34389710 PMCID: PMC8363744 DOI: 10.1038/s41467-021-24928-6] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Accepted: 07/08/2021] [Indexed: 11/15/2022] Open
Abstract
The mammalian sensory neocortex consists of hierarchically organized areas reciprocally connected via feedforward (FF) and feedback (FB) circuits. Several theories of hierarchical computation ascribe the bulk of the computational work of the cortex to looped FF-FB circuits between pairs of cortical areas. However, whether such corticocortical loops exist remains unclear. In higher mammals, individual FF-projection neurons send afferents almost exclusively to a single higher-level area. However, it is unclear whether FB-projection neurons show similar area-specificity, and whether they influence FF-projection neurons directly or indirectly. Using viral-mediated monosynaptic circuit tracing in macaque primary visual cortex (V1), we show that V1 neurons sending FF projections to area V2 receive monosynaptic FB inputs from V2, but not other V1-projecting areas. We also find monosynaptic FB-to-FB neuron contacts as a second motif of FB connectivity. Our results support the existence of FF-FB loops in primate cortex, and suggest that FB can rapidly and selectively influence the activity of incoming FF signals.
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Affiliation(s)
- Caitlin Siu
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT, USA
| | - Justin Balsor
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT, USA
| | - Sam Merlin
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT, USA
- Medical Science, School of Science, Western Sydney University, Campbelltown, NSW, Australia
| | - Frederick Federer
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT, USA
| | - Alessandra Angelucci
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT, USA.
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Habiba U, Merlin S, Lim JKH, Wong VHY, Nguyen CTO, Morley JW, Bui BV, Tayebi M. Age-Specific Retinal and Cerebral Immunodetection of Amyloid-β Plaques and Oligomers in a Rodent Model of Alzheimer's Disease. J Alzheimers Dis 2021; 76:1135-1150. [PMID: 32597800 DOI: 10.3233/jad-191346] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Amyloid-β soluble oligomers (Aβo) are believed to be the cause of the pathophysiology underlying Alzheimer's disease (AD) and are normally detected some two decades before clinical onset of the disease. Retinal pathology associated with AD pathogenesis has previously been reported, including ganglion cell loss, accumulation of Aβ deposits in the retina, and reduction of nerve fiber layer thickness as well as abnormalities of the microvasculature. OBJECTIVE This study's aim is to better understand the relationship between brain and retinal Aβo deposition and in particular to quantify levels of the toxic Aβo as a function of age in the retina of a rodent model of AD. METHODS Retinas and brain tissue from 5×FAD mice were stained with Congo red, Thioflavin-T (Th-T), and Aβ plaque-specific and Aβo-specific antibodies. RESULTS We show that retinas displayed an age-dependent increase of Th-T-specific amyloid fibrils. Staining with anti-Aβ antibody confirmed the presence of the Aβ plaques in all 5×FAD retinas tested. In contrast, staining with anti-Aβo antibody showed an age-dependent decrease of retinal Aβo. Of note, Aβo was observed mainly in the retinal nuclear layers. Finally, we confirmed the localization of Aβo to neurons, typically accumulating in late endosomes, indicating possible impairment of the endocytic pathway. CONCLUSION Our results demonstrate the presence of intraneuronal Aβo in the retina and its accumulation inversely correlated with retinal Aβ plaque deposition, indicating an age-related conversion in this animal model. These results support the development of an early AD diagnostic test targeting Aβo in the eye.
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Affiliation(s)
- Umma Habiba
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Sam Merlin
- School of Science & Health, Western Sydney University, Campbelltown, NSW, Australia
| | - Jeremiah K H Lim
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - Vickie H Y Wong
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - Christine T O Nguyen
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - John W Morley
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
| | - Bang V Bui
- Department of Optometry and Vision Sciences, University of Melbourne, Victoria, Australia
| | - Mourad Tayebi
- School of Medicine, Western Sydney University, Campbelltown, NSW, Australia
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Federer F, Ta'afua S, Merlin S, Hassanpour MS, Angelucci A. Stream-specific feedback inputs to the primate primary visual cortex. Nat Commun 2021; 12:228. [PMID: 33431862 PMCID: PMC7801467 DOI: 10.1038/s41467-020-20505-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Accepted: 12/03/2020] [Indexed: 11/16/2022] Open
Abstract
The sensory neocortex consists of hierarchically-organized areas reciprocally connected via feedforward and feedback circuits. Feedforward connections shape the receptive field properties of neurons in higher areas within parallel streams specialized in processing specific stimulus attributes. Feedback connections have been implicated in top-down modulations, such as attention, prediction and sensory context. However, their computational role remains unknown, partly because we lack knowledge about rules of feedback connectivity to constrain models of feedback function. For example, it is unknown whether feedback connections maintain stream-specific segregation, or integrate information across parallel streams. Using viral-mediated labeling of feedback connections arising from specific cytochrome-oxidase stripes of macaque visual area V2, here we show that feedback to the primary visual cortex (V1) is organized into parallel streams resembling the reciprocal feedforward pathways. This suggests that functionally-specialized V2 feedback channels modulate V1 responses to specific stimulus attributes, an organizational principle potentially extending to feedback pathways in other sensory systems.
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Affiliation(s)
- Frederick Federer
- Department of Ophthalmology and Visual Science Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
| | - Seminare Ta'afua
- Department of Ophthalmology and Visual Science Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
- Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, 84132, USA
| | - Sam Merlin
- Department of Ophthalmology and Visual Science Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
- Medical Science, School of Science, Western Sydney University, Campbelltown, Sydney, NSW, 2560, Australia
| | - Mahlega S Hassanpour
- Department of Ophthalmology and Visual Science Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
| | - Alessandra Angelucci
- Department of Ophthalmology and Visual Science Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA.
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Ho CLA, Zimmermann R, Flórez Weidinger JD, Prsa M, Schottdorf M, Merlin S, Okamoto T, Ikezoe K, Pifferi F, Aujard F, Angelucci A, Wolf F, Huber D. Orientation Preference Maps in Microcebus murinus Reveal Size-Invariant Design Principles in Primate Visual Cortex. Curr Biol 2020; 31:733-741.e7. [PMID: 33275889 PMCID: PMC9026768 DOI: 10.1016/j.cub.2020.11.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Revised: 10/08/2020] [Accepted: 11/11/2020] [Indexed: 01/05/2023]
Abstract
Orientation preference maps (OPMs) are a prominent feature of primary visual cortex (V1) organization in many primates and carnivores. In rodents, neurons are not organized in OPMs but are instead interspersed in a “salt and pepper” fashion, although clusters of orientation-selective neurons have been reported. Does this fundamental difference reflect the existence of a lower size limit for orientation columns (OCs) below which they cannot be scaled down with decreasing V1 size? To address this question, we examined V1 of one of the smallest living primates, the 60-g prosimian mouse lemur (Microcebus murinus). Using chronic intrinsic signal imaging, we found that mouse lemur V1 contains robust OCs, which are arranged in a pinwheel-like fashion. OC size in mouse lemurs was found to be only marginally smaller compared to the macaque, suggesting that these circuit elements are nearly incompressible. The spatial arrangement of pinwheels is well described by a common mathematical design of primate V1 circuit organization. In order to accommodate OPMs, we found that the mouse lemur V1 covers one-fifth of the cortical surface, which is one of the largest V1-to-cortex ratios found in primates. These results indicate that the primate-type visual cortical circuit organization is constrained by a size limitation and raises the possibility that its emergence might have evolved by disruptive innovation rather than gradual change. Orientation preference maps are a hallmark of V1 organization in all primates studied thus far, yet they are absent in rodents. It is uncertain whether these structures scale with body or brain size. Using intrinsic signal imaging, Ho et al. reveal the presence of such maps in the V1 of the world’s smallest primate, the mouse lemur (Microcebus murinus).
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Affiliation(s)
- Chun Lum Andy Ho
- University of Geneva, Department of Basic Neurosciences, Rue Michel Servet 1, Geneva 1211, Switzerland
| | - Robert Zimmermann
- University of Geneva, Department of Basic Neurosciences, Rue Michel Servet 1, Geneva 1211, Switzerland
| | | | - Mario Prsa
- University of Geneva, Department of Basic Neurosciences, Rue Michel Servet 1, Geneva 1211, Switzerland
| | - Manuel Schottdorf
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, Göttingen 37077, Germany
| | - Sam Merlin
- Moran Eye Center, University of Utah, Department of Ophthalmology and Visual Science, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA
| | - Tsuyoshi Okamoto
- Kyushu University, Faculty of Arts and Science, 744 Motooka Nishi-ku, Fukuoka 819-0395, Japan
| | - Koji Ikezoe
- Center for Information and Neural Networks, Osaka University and National Institute of Information and Communications Technology, Graduate School of Frontier Biosciences, 1-3 Yamadaoka Suita, Osaka 565-0871, Japan
| | - Fabien Pifferi
- UMR CNRS/MNHN 7179, Mécanismes Adaptatifs et Evolution, 1 Avenue du Petit Chateau, Brunoy 91800, France
| | - Fabienne Aujard
- UMR CNRS/MNHN 7179, Mécanismes Adaptatifs et Evolution, 1 Avenue du Petit Chateau, Brunoy 91800, France
| | - Alessandra Angelucci
- Moran Eye Center, University of Utah, Department of Ophthalmology and Visual Science, 65 Mario Capecchi Drive, Salt Lake City, UT 84132, USA
| | - Fred Wolf
- Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, Göttingen 37077, Germany; Campus Institute for Dynamics of Biological Networks, Hermann-Rein-Straße 3, Göttingen 37075, Germany; Bernstein Center for Computational Neuroscience, Hermann-Rein-Straße 3, Göttingen 37075, Germany; Max Planck Institute of Experimental Medicine, Hermann-Rein-Straße 3, Göttingen 37075, Germany; Institute for Dynamics of Complex Systems, Georg-August University, Friedrich-Hund-Platz 1, Göttingen 37073, Germany
| | - Daniel Huber
- University of Geneva, Department of Basic Neurosciences, Rue Michel Servet 1, Geneva 1211, Switzerland.
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Bijanzadeh M, Nurminen L, Merlin S, Clark AM, Angelucci A. Distinct Laminar Processing of Local and Global Context in Primate Primary Visual Cortex. Neuron 2018; 100:259-274.e4. [PMID: 30220509 DOI: 10.1016/j.neuron.2018.08.020] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Revised: 07/05/2018] [Accepted: 08/18/2018] [Indexed: 01/19/2023]
Abstract
Visual perception is affected by spatial context. In visual cortex, neuronal responses to stimuli inside the receptive field (RF) are suppressed by stimuli in the RF surround. To understand the circuits and cortical layers processing spatial context, we simultaneously recorded across all layers of macaque primary visual cortex while presenting stimuli at increasing distances from the recorded cells' RF. We find that near versus far-surround stimuli activate distinct layers, thus revealing unique laminar contributions to the processing of local and global spatial context. Stimuli in the near-surround evoke the earliest subthreshold responses in superficial and upper-deep layers, and earliest suppression of spiking responses in superficial layers. Conversely, far-surround stimuli evoke the earliest subthreshold responses in feedback-recipient layer 1 and lower-deep layers, and earliest suppression of spiking responses almost simultaneously in all layers, except 4C, where suppression emerges last. Our results suggest distinct circuits for local and global signal integration.
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Affiliation(s)
- Maryam Bijanzadeh
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT 84132, USA
| | - Lauri Nurminen
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT 84132, USA
| | - Sam Merlin
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT 84132, USA
| | - Andrew M Clark
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT 84132, USA
| | - Alessandra Angelucci
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, UT 84132, USA.
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12
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Nurminen L, Merlin S, Bijanzadeh M, Federer F, Angelucci A. Top-down feedback controls spatial summation and response amplitude in primate visual cortex. Nat Commun 2018; 9:2281. [PMID: 29892057 PMCID: PMC5995810 DOI: 10.1038/s41467-018-04500-5] [Citation(s) in RCA: 101] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2017] [Accepted: 04/25/2018] [Indexed: 12/25/2022] Open
Abstract
Sensory information travels along feedforward connections through a hierarchy of cortical areas, which, in turn, send feedback connections to lower-order areas. Feedback has been implicated in attention, expectation, and sensory context, but the mechanisms underlying these diverse feedback functions are unknown. Using specific optogenetic inactivation of feedback connections from the secondary visual area (V2), we show how feedback affects neural responses in the primate primary visual cortex (V1). Reducing feedback activity increases V1 cells' receptive field (RF) size, decreases their responses to stimuli confined to the RF, and increases their responses to stimuli extending into the proximal surround, therefore reducing surround suppression. Moreover, stronger reduction of V2 feedback activity leads to progressive increase in RF size and decrease in response amplitude, an effect predicted by a recurrent network model. Our results indicate that feedback modulates RF size, surround suppression and response amplitude, similar to the modulatory effects of visual spatial attention.
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Affiliation(s)
- Lauri Nurminen
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
| | - Sam Merlin
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
- Medical Science, School of Science and Health, Western Sydney University, Campbelltown, NSW, 2560, Australia
| | - Maryam Bijanzadeh
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
- Department of Neurological Surgery, UCSF, San Francisco, CA, 94143, USA
| | - Frederick Federer
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA
| | - Alessandra Angelucci
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, 65 Mario Capecchi Drive, Salt Lake City, UT, 84132, USA.
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13
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Ebel A, Guis L, Merlin S. Infections à Chlamydia trachomatis : données épidémiologiques récentes dans un laboratoire spécialisé. Med Mal Infect 2018. [DOI: 10.1016/j.medmal.2018.04.241] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
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14
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Boutte RW, Merlin S, Yona G, Griffiths B, Angelucci A, Kahn I, Shoham S, Blair S. Utah optrode array customization using stereotactic brain atlases and 3-D CAD modeling for optogenetic neocortical interrogation in small rodents and nonhuman primates. Neurophotonics 2017; 4:041502. [PMID: 28721358 PMCID: PMC5506344 DOI: 10.1117/1.nph.4.4.041502] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 06/08/2017] [Indexed: 05/11/2023]
Abstract
As the optogenetic field expands, the need for precise targeting of neocortical circuits only grows more crucial. This work demonstrates a technique for using Solidworks® computer-aided design (CAD) and readily available stereotactic brain atlases to create a three-dimensional (3-D) model of the dorsal region of area visual cortex 4 (V4D) of the macaque monkey (Macaca fascicularis) visual cortex. The 3-D CAD model of the brain was used to customize an [Formula: see text] Utah optrode array (UOA) after it was determined that a high-density ([Formula: see text]) UOA caused extensive damage to marmoset (Callithrix jacchus) primary visual cortex as assessed by electrophysiological recording of spiking activity through a 1.5-mm-diameter through glass via. The [Formula: see text] UOA was customized for optrode length ([Formula: see text]), optrode width ([Formula: see text]), optrode pitch ([Formula: see text]), backplane thickness ([Formula: see text]), and overall form factor ([Formula: see text]). Two [Formula: see text] UOAs were inserted into layer VI of macaque V4D cortices with minimal damage as assessed in fixed tissue cytochrome oxidase staining in nonrecoverable surgeries. Additionally, two [Formula: see text] arrays were implanted in mice (Mus musculus) motor cortices, providing early evidence for long-term tolerability (over 6 months), and for the ability to integrate the UOA with a Holobundle light delivery system toward patterned optogenetic stimulation of cortical networks.
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Affiliation(s)
- Ronald W. Boutte
- University of Utah, Department of Electrical and Computer Engineering, Salt Lake City, Utah, United States
- Northrop Grumman Corporation, Salt Lake City, Utah, United States
- Address all correspondence to: Ronald W. Boutte, E-mail: ; Steve Blair, E-mail:
| | - Sam Merlin
- University of Utah, Moran Eye Institute, Department of Ophthalmology, Salt Lake City, Utah, United States
| | - Guy Yona
- Technion–Israel Institute of Technology, Haifa, Israel
| | | | - Alessandra Angelucci
- University of Utah, Moran Eye Institute, Department of Ophthalmology, Salt Lake City, Utah, United States
| | - Itamar Kahn
- Technion–Israel Institute of Technology, Haifa, Israel
| | - Shy Shoham
- Technion–Israel Institute of Technology, Haifa, Israel
| | - Steve Blair
- University of Utah, Department of Electrical and Computer Engineering, Salt Lake City, Utah, United States
- Address all correspondence to: Ronald W. Boutte, E-mail: ; Steve Blair, E-mail:
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15
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Abstract
Surround modulation (SM) is a fundamental property of sensory neurons in many species and sensory modalities. SM is the ability of stimuli in the surround of a neuron's receptive field (RF) to modulate (typically suppress) the neuron's response to stimuli simultaneously presented inside the RF, a property thought to underlie optimal coding of sensory information and important perceptual functions. Understanding the circuit and mechanisms for SM can reveal fundamental principles of computations in sensory cortices, from mouse to human. Current debate is centered over whether feedforward or intracortical circuits generate SM, and whether this results from increased inhibition or reduced excitation. Here we present a working hypothesis, based on theoretical and experimental evidence, that SM results from feedforward, horizontal, and feedback interactions with local recurrent connections, via synaptic mechanisms involving both increased inhibition and reduced recurrent excitation. In particular, strong and balanced recurrent excitatory and inhibitory circuits play a crucial role in the computation of SM.
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Affiliation(s)
- Alessandra Angelucci
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, Utah 84132; , , , ,
| | - Maryam Bijanzadeh
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, Utah 84132; , , , ,
| | - Lauri Nurminen
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, Utah 84132; , , , ,
| | - Frederick Federer
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, Utah 84132; , , , ,
| | - Sam Merlin
- Department of Ophthalmology and Visual Science, Moran Eye Institute, University of Utah, Salt Lake City, Utah 84132; , , , ,
| | - Paul C Bressloff
- Department of Mathematics, University of Utah, Salt Lake City, Utah 84132;
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16
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Ebel A, Bali C, Guis L, Merlin S. Performance evaluation of the Aptima® HIV-1 Quant Dx and Aptima® HBV Quant assays on the fully automated Panther in comparison to COBAS® AmpliPrep/COBAS® TaqMan® HIV-1 and HBV tests. J Clin Virol 2016. [DOI: 10.1016/j.jcv.2016.08.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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17
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Mokhtari C, Ebel A, Reinhardt B, Merlin S, Proust S, Roque-Afonso AM. Charaterization of samples with HCV genotype 1 with no subtype results by Abbott RealTime HCV Genotype II assay using an additional real-time test. J Clin Virol 2015. [DOI: 10.1016/j.jcv.2015.07.259] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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18
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Nguyen L, Deschaght P, Merlin S, Loywick A, Audebert C, Viscogliosi E, Vaneechoutte M, Delhaes L. 49 Propidium monoazide (PMA) sample pretreatment impacts the abundance of rare populations in high-throughput sequencing analysis of CF lung mycobiome and bacteriome. J Cyst Fibros 2015. [DOI: 10.1016/s1569-1993(15)30226-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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19
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Seesao Y, Audebert C, Verrez-Bagnis V, Merlin S, Jérôme M, Viscogliosi E, Dei-Cas E, Aliouat-Denis CM, Gay M. Monitoring of four DNA extraction methods upstream of high-throughput sequencing of Anisakidae nematodes. J Microbiol Methods 2014; 102:69-72. [PMID: 24845469 DOI: 10.1016/j.mimet.2014.05.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Revised: 05/09/2014] [Accepted: 05/09/2014] [Indexed: 11/18/2022]
Abstract
Different methods were evaluated to extract DNA from pooled nematodes belonging to Anisakis, Contracaecum, Pseudoterranova and Hysterothylacium genera isolated from edible fish. Pooled DNA extraction is the first and compulsory step to allow the identification of a large number of samples through high-throughput DNA sequencing with drastic time and cost reductions.
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Affiliation(s)
- Y Seesao
- ANSES, Lab. Sécurité des Aliments, Dept Produits de la Pêche et de l'Aquaculture, Boulogne-sur-mer, France; Biologie et Diversité des Pathogènes Eucaryotes Emergents, Institut Pasteur de Lille (IPL), Centre d'Infection et d'Immunité de Lille (CIIL), UMR CNRS 8204, Inserm U1019, Univ. Lille Nord de France, France
| | - C Audebert
- Gènes Diffusion, Douai, France; PEGASE-Biosciences, Institut Pasteur de Lille, France
| | | | - S Merlin
- Gènes Diffusion, Douai, France; PEGASE-Biosciences, Institut Pasteur de Lille, France
| | | | - E Viscogliosi
- Biologie et Diversité des Pathogènes Eucaryotes Emergents, Institut Pasteur de Lille (IPL), Centre d'Infection et d'Immunité de Lille (CIIL), UMR CNRS 8204, Inserm U1019, Univ. Lille Nord de France, France
| | - E Dei-Cas
- Biologie et Diversité des Pathogènes Eucaryotes Emergents, Institut Pasteur de Lille (IPL), Centre d'Infection et d'Immunité de Lille (CIIL), UMR CNRS 8204, Inserm U1019, Univ. Lille Nord de France, France
| | - C M Aliouat-Denis
- Biologie et Diversité des Pathogènes Eucaryotes Emergents, Institut Pasteur de Lille (IPL), Centre d'Infection et d'Immunité de Lille (CIIL), UMR CNRS 8204, Inserm U1019, Univ. Lille Nord de France, France.
| | - M Gay
- ANSES, Lab. Sécurité des Aliments, Dept Produits de la Pêche et de l'Aquaculture, Boulogne-sur-mer, France
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20
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Dautigny M, Ebel A, Merlin S, Souchet A, Ronsin C. P3.092 Prevalence of Trichomonas Vaginalisin France and Comparison with Chlamydia Trachomatisand Neisseria Gonorrhoeaeas Determined by the APTIMA Trichomonas Vaginalis Nucleic Acid Amplification Assay. Br J Vener Dis 2013. [DOI: 10.1136/sextrans-2013-051184.0551] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
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21
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Merlin S, Horng S, Marotte LR, Sur M, Sawatari A, Leamey CA. Deletion of Ten-m3 induces the formation of eye dominance domains in mouse visual cortex. ACTA ACUST UNITED AC 2012; 23:763-74. [PMID: 22499796 DOI: 10.1093/cercor/bhs030] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The visual system is characterized by precise retinotopic mapping of each eye, together with exquisitely matched binocular projections. In many species, the inputs that represent the eyes are segregated into ocular dominance columns in primary visual cortex (V1), whereas in rodents, this does not occur. Ten-m3, a member of the Ten-m/Odz/Teneurin family, regulates axonal guidance in the retinogeniculate pathway. Significantly, ipsilateral projections are expanded in the dorsal lateral geniculate nucleus and are not aligned with contralateral projections in Ten-m3 knockout (KO) mice. Here, we demonstrate the impact of altered retinogeniculate mapping on the organization and function of V1. Transneuronal tracing and c-fos immunohistochemistry demonstrate that the subcortical expansion of ipsilateral input is conveyed to V1 in Ten-m3 KOs: Ipsilateral inputs are widely distributed across V1 and are interdigitated with contralateral inputs into eye dominance domains. Segregation is confirmed by optical imaging of intrinsic signals. Single-unit recording shows ipsilateral, and contralateral inputs are mismatched at the level of single V1 neurons, and binocular stimulation leads to functional suppression of these cells. These findings indicate that the medial expansion of the binocular zone together with an interocular mismatch is sufficient to induce novel structural features, such as eye dominance domains in rodent visual cortex.
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Affiliation(s)
- Sam Merlin
- Discipline of Physiology, School of Medical Sciences and the Bosch Institute, University of Sydney, Sydney, New South Wales 2006, Australia
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22
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Leamey CA, Merlin S, Lattouf P, Sawatari A, Zhou X, Demel N, Glendining KA, Oohashi T, Sur M, Fässler R. Ten_m3 regulates eye-specific patterning in the mammalian visual pathway and is required for binocular vision. PLoS Biol 2007; 5:e241. [PMID: 17803360 PMCID: PMC1964777 DOI: 10.1371/journal.pbio.0050241] [Citation(s) in RCA: 115] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Accepted: 07/09/2007] [Indexed: 11/18/2022] Open
Abstract
Binocular vision requires an exquisite matching of projections from each eye to form a cohesive representation of the visual world. Eye-specific inputs are anatomically segregated, but in register in the visual thalamus, and overlap within the binocular region of primary visual cortex. Here, we show that the transmembrane protein Ten_m3 regulates the alignment of ipsilateral and contralateral projections. It is expressed in a gradient in the developing visual pathway, which is consistently highest in regions that represent dorsal visual field. Mice that lack Ten_m3 show profound abnormalities in mapping of ipsilateral, but not contralateral, projections, and exhibit pronounced deficits when performing visually mediated behavioural tasks. It is likely that the functional deficits arise from the interocular mismatch, because they are reversed by acute monocular inactivation. We conclude that Ten_m3 plays a key regulatory role in the development of aligned binocular maps, which are required for normal vision. The visual world is represented within the brain as a series of maps of visual space. In species with binocular vision, the inputs from the two eyes are aligned to form a cohesive map; little is known about how this organisation is achieved during development. We show that a transmembrane protein, Ten_m3, plays an important role. Ten_m3 is required for the guidance of uncrossed retinal axons: uncrossed projections from the eye to the brain map aberrantly in mice that lack Ten_m3, although crossed projections map normally. Consequently, projections from the two eyes are not aligned in these mice. We show that this mismatch has devastating consequences for vision. Mice lacking Ten_m3 perform very poorly in behavioural tests of visual function. The deficits are a direct result of the mismatch, because acutely silencing inputs from one eye restores visual behaviour. This remarkable and rapid recovery suggests the mismatch of the inputs from the two eyes leads to functional suppression in the brain. We conclude that Ten_m3 acts as an eye-specific guidance cue for retinal axons and is required to produce aligned projections from the two eyes, and further, that this is critical for normal visual function. Ten_m3, a transmembrane protein, has a newly discovered role in guiding retinal axons, aligning projections from the two eyes, and thereby mediating binocular vision.
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Affiliation(s)
- Catherine A Leamey
- Department of Physiology, Bosch Institute and School of Medical Sciences, University of Sydney, Sydney, Australia.
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23
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Lee SC, Ibdah R, Van Valkenburgh C, Rowold E, Abegg A, Donnelly A, Klover J, Merlin S, McKearn JP. Phage display mutagenesis of the chimeric dual cytokine receptor agonist myelopoietin. Leukemia 2001; 15:1277-85. [PMID: 11480572 DOI: 10.1038/sj.leu.2402163] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Myelopoietins comprise a class of chimeric cytokine receptor agonists consisting of an hIL-3 (human interleukin-3) receptor agonist and an hG-CSF (human granulocyte colony-stimulating factor) receptor agonist linked head-to-tail at their respective carboxy and amino termini. The combination of an early acting cytokine (hIL-3) with a late acting one (hG-CSF) allows efficient hematopoeitic reconstruction following myeloablative insult, and drives differentiation of non-myelocytic lineages (ie thrombocytic lineages) that are inaccessible using hG-CSF alone, in both preclinical models and clinical settings. A myelopoietin species was displayed and mutagenized on filamentous bacteriophage: both component agonists of myelopoietin were presented in biologically functional conformations as each recognized its corresponding receptor. Five amino acid positions in a short region of the hG-CSF receptor agonist module of myelopoietin that had been identified as important for proliferative activity were mutagenized. Display was used because it allows very 'deep' mutagenesis at selected residues: >10(5) substitution variants were affinity-screened using the hG-CSF receptor and 130 new, active variants of myelopoietin were identified and characterized. None of the selected variants were significantly more active than the parental myelopoietin species in a hG-CSF-dependent cell proliferation assay, though many were as active. Many of these relatively high-activity variants contained parental amino acids at several positions, suggesting the parental sequence may already be optimal at these positions for the assays used, and potentially accounting for the failure to identify enhanced bioactivity variants. Analysis of substitutions of high-activity variants complements and extends previous alanine scanning, and other genetic and biochemical data for hG-CSF variants.
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Affiliation(s)
- S C Lee
- GD Searle Pharmacia Company, St Louis, MO 63196, USA
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24
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Köchli C, Wendland T, Frutig K, Grunow R, Merlin S, Pichler WJ. CD80 and CD86 costimulatory molecules on circulating T cells of HIV infected individuals. Immunol Lett 1999; 65:197-201. [PMID: 10065743 DOI: 10.1016/s0165-2478(98)00107-2] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The expression of CD80 and CD86 costimulatory molecules, typical for antigen presenting cells (APC), was measured on circulating T cells of 20 HIV-infected individuals and of 11 HIV-negative healthy controls. The CD80 and CD86 molecules were present on both circulating T subsets of HIV-infected individuals (mean of CD80 expression within CD4+ T cells [CD80/CD4]: 5.0%; and CD86/CD4: 2.6%; CD80/CD8 4.1% and CD86/CD8: 2.7%) and were associated with HLA-DR expression. Some CD80 and CD86 expression was also found in normal controls, and only the expression of CD86 was significantly (P < 0.05) increased on CD4 + and CD8 + T cells of HIV-infected individuals. The expression of CD28 was decreased on T cells of HIV-infected individuals and was negatively correlated to the expression of HLA-DR and CD86 (mean CD28 within CD3+T cells: HIV+ 29.5%, HIV - 67.6%; correlation coefficient, - 0.75 and - 0.71, respectively). The more the disease proceeds, the less CD28 and the more DR and CD86 are found on circulating T cells. This suggests that during HIV infection T cells themselves develop an antigen presenting phenotype by upregulating expression of HLA-DR, CD86 and CD80 molecules.
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Affiliation(s)
- C Köchli
- Institute of Immunology and Allergology, Inselspital Bern, Switzerland
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25
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Merlin S, Rowold E, Abegg A, Berglund C, Klover J, Staten N, McKearn JP, Lee SC. Phage presentation and affinity selection of a deletion mutant of human interleukin-3. Appl Biochem Biotechnol 1997; 67:199-214. [PMID: 9332969 DOI: 10.1007/bf02788798] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
A deletion derivative of the cytokine human interleukin-3 (hIL-3(15-125), comprising amino acids 15-125 of the native protein) was produced as a fusion to the filamentous phage surface protein pIII. The cytokine was detected in association with phage particles by protein immunoblotting. Compared to an equivalent quantity of soluble-cytokine, phage-presented hIL-3(15-125) exhibited reduced biological activity in a hIL-3-dependent cell proliferation assay. The reduction in activity was attributable to presence of phage particles in the assay, rather than directly owing to physical incorporation of the cytokine into the phage particle. Owing to the position of the amber codon in the phagemid vector, the phagemid-produced free hIL-3(15-125) species (designated hIL-3(15-125) epsilon) had 20 amino acids appended to its C-terminus; hIL-3(15-125) epsilon did not exhibit reduced bioactivity. hIL-3(15-125)-presenting phage were affinity-selected with either a hIL-3-reactive polyclonal antibody or with cells expressing the heterodimeric hIL-3 receptor. These data are consistent with the use of phage-display technology for the affinity selection of hIL-3 variants with modified biological properties.
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Affiliation(s)
- S Merlin
- Searle Research and Development, Monsanto Company, St. Louis, MO 63198, USA
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26
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Abstract
Two quantitative models of plasmid ColE1 copy number control are compared with respect to mathematical logic of derivation and application to experimental observations. Explanatory background material and clarifications are supplied for selected aspects of each model. Contrasting features are emphasized and experiments are suggested to distinguish between predictions of the models.
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Affiliation(s)
- S Merlin
- Department of Biology, Indiana University, Bloomington 47401, USA
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27
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Croize J, Gialanella P, Monnet D, Okada J, Orsi A, Voss A, Merlin S. Improved identification of Staphylococcus aureus using a new agglutination test. Results of an international study. APMIS 1993; 101:487-91. [PMID: 8363825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
A new reagent for the identification of Staphylococcus aureus, SLIDEX STAPH-KIT, operates on the principle of a latex and red blood cell combination agglutination: red blood cells are coated with fibrinogen for the detection of clumping factor, and latex particles are sensitized with anti-S. aureus serotype 18 monoclonal antibody for the detection of protein A and antigen 18. French strains belonging to serotype 18 are methicillin-resistant. The performance of this reagent was compared with STAPHYSLIDE and STAPHAUREX in Europe (France, Germany, Italy), in the United States and in Japan using 548 methicillin-resistant S. aureus strains, 392 methicillin-sensitive S. aureus strains, and 441 non-aureus staphylococci. The specificity of the three reagents was equivalent (98.8% for SLIDEX STAPH-KIT, 99.1% for STAPHYSLIDE, 98.1% for STAPHAUREX). SLIDEX STAPH-KIT (97.3%) was more sensitive than STAPHYSLIDE (93.5%) and STAPHAUREX (89.7%) for all S. aureus strains due to a higher rate of identified methicillin-resistant S. aureus strains.
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Affiliation(s)
- J Croize
- Department of Microbiology, Michallon Hospital, Grenoble, France
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Abstract
The replication regulatory mechanisms by which the small, multicopy plasmid ColE1 maintains a constant steady-state copy number have been extensively characterized by a combination of in vivo genetics and in vitro biochemistry. We have extended the analysis of replication control into the "establishment" phase of replication, when ColE1-directed replicons replicate more than once per cell generation and the intracellular concentrations of plasmid-encoded replication regulatory elements are changing. To study establishment phase replication, in which plasmid-directed replicons amplify from an initially low concentration to the characteristic, steady-state concentration, bacteriophage-plasmid hybrids, termed phasmids, were constructed. Phasmids were shown to exhibit stability, segregation, and incompatibility properties similar to those of the parent plasmid. Establishment phase replication was analyzed by measuring the number of phasmids per cell as a function of time after infection. We observed a linear increase in phasmid concentration until the steady-state concentration characteristic of the ColE1 plasmid component of the hybrid was reached. The number of cell doublings required for the phasmid concentration to reach steady-state was inversely related to cell growth rate. The observed amplification kinetics imply that the frequency of replication initiation per phasmid continually decreases until steady-state is reached. Kinetics of establishment phase amplification were sensitive to rate of expression of RNA II. A phasmid containing an up mutation in the RNA II promoter amplified at a 15-fold faster rate than the wild-type phasmid. Concentration of the ColE1 replication negative regulator (RNA I) was proportional to phasmid concentration throughout the amplification phase. These results suggest that the same elements that regulate steady-state replication also control establishment phase replication.
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Affiliation(s)
- S Merlin
- Department of Biology, Indiana University, Bloomington 47405
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Abstract
Plasmid ColE1 has three recognition sites for the Escherichia coli DNA adenine methylase in the immediate upstream region of the primer promoter. Two of these sites are conserved among all plasmid relatives of ColE1 and constitute parts of an inverted repeat that can conceivably form a cruciform structure. Recent experiments have indicated that hemimethylated ColE1-type plasmids are inefficiently replicated after transformation (D. W. Russell and N. Zinder, Cell 50:1071-1079, 1987). By mutating the three methylation sites, we found that disruption of all three GATC sites was necessary for complete relief of the hemimethylation-mediated inhibition of replication in vivo. We also found that these three methylation sites acted in a position-specific manner. The putative cruciform, if present, did not play a regulatory role in the hemimethylation-mediated inhibition of replication.
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Affiliation(s)
- P K Patnaik
- Department of Biology, Indiana University, Bloomington 47405
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Merlin S, Poncet F, Alacoque B, Guinet R, André J. Treponemal antigens detected by immunoblotting with serum and CSF antibodies of neurosyphilitic patients. Ann Inst Pasteur Microbiol 1987; 138:709-17. [PMID: 3331295 DOI: 10.1016/0769-2609(87)90148-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Treponemal-antigen-eliciting antibodies in neurosyphilis were investigated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis immunoblotting with 17 sera and cerebrospinal fluid (CSF) (16 pairs) from 10 neurosyphilitic patients. Sera and CSF detected identical proteins. IgG antibodies in sera and CSF mainly revealed Treponema pallidum proteins of MW 48, 45, 38 and 37 Kd, and T. phagedenis proteins of MW 59, 54, 41, 40, 35 and 33 Kd. Few proteins were detected by IgM antibodies. Although no particular protein elicited antibodies specific for neurosyphilis, the immunoblot detection of antibodies to T. pallidum or T. phagedenis antigens in CSF or sera should be useful as a diagnostic tool for neurosyphilis.
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Affiliation(s)
- S Merlin
- Service de Sérologie Nelson, Institut Pasteur, Lyon, France
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Merlin S, Andre J, Alacoque B, Paris-Hamelin A. Importance of specific IgM antibodies in 116 patients with various stages of syphilis. Genitourin Med 1985; 61:82-7. [PMID: 3884486 PMCID: PMC1011772 DOI: 10.1136/sti.61.2.82] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
We tested 222 serum samples obtained from 51 patients presenting with syphilis, before and after treatment; 117 from 65 patients with a history of syphilis (114) or yaws (3); 77 from 71 patients with no evidence of syphilis; and 1117 serologically negative serum samples. Our tests included the IgM fluorescent treponemal antibody absorbed (IgM-FTA-ABS) and solid phase haemadsorption assay (SPHA) techniques. According to the stage of development of syphilis, IgM antibodies were found in 83-100% of the serum samples. This permitted a precise diagnosis to be made and cure assessed. As IgM antibodies were absent in serum from patients with healed syphilis, resolved syphilis could be distinguished from developing syphilis. The sensitivity (92%) of the IgM-FTA-ABS test was comparable with that of the SPHA (96%), but the SPHA was more specific (97.4%) than the IgM-FTA-ABS test (89.61%).
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Merlin S, André J, Alacoque B. [Diagnosis of syphilis. Value of the determination of specific immunoglobulins M by solid-phase hemadsorption]. Presse Med 1984; 13:2269. [PMID: 6239180] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
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Kaliner M, Dyer J, Merlin S, Shelton A, Greenhill A, Treadwell G, McKenna W, Lieberman P. Increased urine histamine and contrast media reactions. Invest Radiol 1984; 19:116-8. [PMID: 6533100 DOI: 10.1097/00004424-198403000-00007] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Urine samples were collected from 200 subjects undergoing intravenous pyelography. The urine histamine levels were compared with those of 132 normal control subjects, 11 subjects with systemic mastocytosis, six subjects with idiopathic anaphylaxis, and ten subjects experiencing mild anaphylactic reactions during allergy immunotherapy. Compared with normal controls, as a group, all subjects receiving intravenous contrast media had increased urine histamine (P less than 0.05 by Student's t-test) while those subjects experiencing adverse reactions had considerably larger increases. The urine histamine levels in the subjects experiencing systemic reactions were in the same range as those observed in patients having mild anaphylactic reactions to immunotherapy and somewhat lower than those found in idiopathic anaphylaxis or systemic mastocytosis. These data suggest that some histamine release accompanies infusions of contrast media in all subjects and that larger amounts of histamine release are associated with adverse reactions.
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Warren K, Dyer J, Merlin S, Kaliner M. Measurement of urinary histamine: comparison of fluorometric and radioisotopic-enzymatic assay procedures. J Allergy Clin Immunol 1983; 71:206-11. [PMID: 6401774 DOI: 10.1016/0091-6749(83)90101-x] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Assessment of urinary histamine may prove useful in determining the role of histamine in human health and disease. Urinary histamine may be accurately estimated by a modified fluorometric assay employing diamine oxidase (DAO) digestion and cation-exchange chromatography. Normal urine histamine values obtained by this assay are: arithmetic means (+/- SEM), 8.6 +/- 0.6 ng/ml and 10.5 +/- 0.7 micrograms/24 hr; geometric means (+/- SEM), 6.2 +/- 1.1 ng/ml and 10.0 +/- 1.3 micrograms/24 hr. However, the radioisotopic-enzymatic assay is less expensive, easier to perform, and possibly more sensitive. Therefore the two procedures were compared. The radioenzyme assay was found to be affected by factors in urine (possibly salt concentrations) requiring extraction of histamine from urine by butanol-heptane. Moreover, it was found to be necessary to compare DAO-digested samples with undigested samples to accurately estimate histamine levels and to run the standard curve of histamine in DAO-digested urine. Even with these modifications, the radioenzyme assay was not as accurate as the fluorometric assay for urine samples having histamine values about 60 ng/ml. Therefore we recommend utilization of the modified fluorometric assay for the measurement of urinary histamine levels.
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Dyer J, Warren K, Merlin S, Metcalfe DD, Kaliner M. Measurement of plasma histamine: description of an improved method and normal values. J Allergy Clin Immunol 1982; 70:82-7. [PMID: 7096824 DOI: 10.1016/0091-6749(82)90233-0] [Citation(s) in RCA: 74] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The single isotopic-enzymatic assay of histamine was modified to increase its sensitivity and to facilitate measurement of plasma histamine levels. The modification involved extracting 3H-1-methylhistamine (generated by the enzyme N-methyltransferase acting on histamine in the presence of S-[methyl-3H]-adenosyl-L-methionine) into chloroform and isolating the 3H-1-methylhistamine by thin-layer chromatography (TLC). The TLC was developed in acetone:ammonium hydroxide (95:10), and the methylhistamine spot (Rf = 0.50) was identified with an o-phthalaldehyde spray, scraped from the plate, and assayed in a scintillation counter. The assay in plasma demonstrated a linear relationship from 200 to 5000 pg histamine/ml. Plasma always had higher readings than buffer, and dialysis of plasma returned these values to the same level as buffer, suggesting that the baseline elevations might be attributable to histamine. However, all histamine standard curves were run in dialyzed plasma to negate any additional influences plasma might exert on the assay. The arithmetic mean (+/- SEM) in normal plasma histamine was 318.4 +/- 25 pg/ml (n = 51), and the geometric mean was 280 +/- 35 pg/ml. Plasma histamine was significantly elevated by infusion of histamine at 0.05 to 1.0 micrograms/kg/min or by cold immersion of the hand of a cold-urticaria patient. Therefore this modified isotopic-enzymatic assay of histamine is extremely sensitive, capable of measuring fluctuations in plasma histamine levels within the normal range, and potentially useful in analysis of the role histamine plays in human physiology.
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